: I'll look into the melamine covered particleboard. Looks like the
: local big box carries it, in the guise of shelf boards. I'll
: have to piece them together, rather than getting one big
: sheet... looks like the widest they've got is 16".

What town are you near? We may be able to find some 4xx8 sheets near you. The Lowes could probably order some for you if you ask. Ordering plastic-covered panels is much simpler than ordering natural wood. They are all uniform. Big sheets of plywood and particleboard can have the corners damages during shipping. The Menards store near me puts these damaged panel in a special bin and slashes the prices on them. If you are not using a full sheet and don't mind amking another cut, you can save a lot.

: The bottom shelf will have supports every 24" (4' wide, edge
: supports and center). I figure the workspace may need more
: rigidity &/or support, so my original plans included a 2x4
: every 10 to 14". That new circular saw is heavy. That vise
: is heavy, too.

: Local Lowe's has a panel saw... they were repairing it the last
: time I was in there. Getting a sheet cut down to 36" wide
: won't be a problem, and it'll actually fit in my Outback.

Getting materials in a size that you can actually take home with you is something people tend to overlook. I bought a 4x8 trailers many years ago (about $200 for the frame plus $60 for wood for floor and sides) and drag that behind my compact car when I go to buy lumber. It was a more-economical arrangement than buying a pickup truck. Some day I'll build a boat rack on that trailer frame. I don't need to carry that many boat right now, but i can see mor use for it.

: Top's gonna be 36" deep. That places the rear edge just within
: my grasp, in case I opt to use the rear as another shelf with
: workspace in front of it. Gives me plenty of workspace. I failed
: to consider the benefits of an overhang, though... I may regret
: going 36". Ah, well. If, by some miracle, the top actually
: comes out rather flat, I may use it for building model aircraft.
: I've got a smaller table with a top I know is flat, though, so I
: don't know how likely this case is.

36" is a good size for most workbenches because most workbenches cn be moved away from the wall so the builder can approach things from either side. If you haven't gotten much further than your pictures indicate, stop now and re-assess three elements of your design. One would be the overhang of the top, next would be the kickspace under the bottom shelf. Then consider whether you want the workbench permanently fastened to shelves.

Looking at that last point first: Vibrations from powertools, like routers, and orbital sanders shake the workbench. Een very sturdy workbenches will transmit those vibrations to the shelves, and you will have small boxes actually walk off the shelves and fall onto your work. the last thing you want is for a small box of screws to fall onto your powertool. It is bad for blades, and a table-mounted router will chew through the box and spit out screws like shrapnel. With a 36" wide top you say you can just reach the back of the table. How are you going to reach the back of a shelf 18" or more above the tabletop? Climb on the workbench? Set a ladder next to the workbench and then lean 3 feet out to get to the shelf? Nothing safe in any of these scenarios. I'd strong ly suggest you build a free-standing workbench you can push in fron of your shelves, or pull out if you need access to the shelves, or the back edge of the workbench. You'll need to add two more legs to your design, and remove the few boards you have attached to the wall uprights. At this point it won't be a lot of work or great cost. In fact, you can probably save money by making the frame 30 to 28 inches wide and getting a 3" to 4" overhang on each side. That also gives you better shelf and top support and a kickspace of over 4".

: Thanks for the insight!

Take a look at the drawing below, and in the next posting. This is how I think you'll like the top, and the next one is how I think you can do the shelf under it. I made the top an inch wider (37") as that is what you get when using 4 2x10 boards. If you want to stick to 36", rip an inch off of one of the 2x10s in the middle. The frame is narrower and maybe a bit shorter than what you planned. This gives a nice overhang on all sides so you can clamp things to the edges of the workbench. You are working with 2x4s for the legs, and that should be fine, but there are a lot of benches with 4x4 legs. Feel free to upsize or to use doubled 2x4s for the legs. If you double up on 2x4s, place your second 2x4 directly under the crosspieces which supports the top. That gives them added strength.

Make the length to fit the same space as you are planning now and the freestanding workbench will slide into place. I also think you should consider a 2x6 for the front rail of the workbench. This is the area where you will be doing most of your pounding, and it should be strong. If you want to, go with a 2x6 for the back rail, too. I'm not sure how long the bench is going to be, but anything over 5 or 6 feet and you might notice some sag if you just use a 2x4.

Judicious use of 3/8" bolts will make it possible for you to disassemble the workbench should you ever move. I suggest making the bottom shelf frame and top as one unit, and bolting that to the legs. The workbench top is a second unit. Just unbolt the legs and the thing becomes manageable pieces.

Lots of my opinions here. I hope some of them help.

PGJ